Landing a Hawker Hurricane from CAT 2 ILS approach.

[Centaurus]

Browsing through RAF Air Publication 1564B & D for Hawker Hurricane 2A,2B,2C,2D and 4 aircraft with Merlin XX engine. Date 1943.

In section 2 it states for instrument let down, for:
Preliminary Approach height 1500 feet IAS 120 mph.
At Outer Marker Beacon: Height 600 feet speed 95-100 mph.
At Inner Marker Beacon. Height 100 feet speed 90-95 mph.

Question.

100 feet Decision Height in the primitive cockpit of a Hurricane (by todays standards) is Cat 2 ILS minima today. That would require superb manual instrument flying skills. One rarely sees those sort of skills nowadays.

If not using an ILS with associated marker beacons, what instrument landing approach would have been used in those days to ensure tracking accuracy for the equivalent of a Cat 2 ILS?

Would that have been a GCA in 1943? if so, would the GCA in those days have marker beacons (aural only or cockpit lights) for height checks. Or would that be a BABS beam approach in 1943?

[Fareastdriver]

Beam Approach System. I last flew it at Tern Hill in 1960. It consisted of an MF beacon that radiated along the approach path giving continuous 'A's when port of track and continuous 'N's when starboard. When on track they merged to a continuous note. There was an outer and inner marker which where passed at a certain height. IIRC these were 1,500 ft. and 100 ft..

There was a more refined version used in multis that had an instrument similar to an ILS indicator but these would not have been fitted to a Hurricane.

When used for the opposite runway then the 'A's and 'N's would be transposed.

[Pom Pax]

When used for the opposite runway then the 'A's and 'N's would be transposed

I assume by driving the van to the other end.

[Fareastdriver]

The beam approach system didn't have a van. It was a fixed aerial also used for navigation similar to a beacon. It had four segments with the NE and SW radiating 'N's and the opposite radiating 'A's. The idea was to be able to position oneself without an ADF needle as at that time homing was manual with a loop aerial. The beacon would be aligned with the runway but would be some distance away so an approach to either end of the runway would involve remembering whether the 'A's were supposed to be on the left or the right.

The BABS van was parked near the threshold and as I saw at Aldergrove in about 1950 a Halifax undershooting could do a splendid job of flattening it. The Hillman hung on the port undercarriage though so the Halifax ended up sprawled over the side of the runway; never to fly again.

Halifax 1 Hillman 1

[Dave Hadfield]

When you're stuck -- running out of gas, with no alternates -- you let-down with whatever you have.


There's no other option.


And then, when you have a glimpse of the ground, you hope it's something you recognize.


If not, in a Hurricane in 1943, you climb back up and bail out.


There's no ILS and no Cat III.


That's not to say it can't be done. Alex Henshaw apparently did it regularly using the plume of smoke from the factory. That plume would emerge from the low overcast and allow him to locate himself. He'd then use his compass and align on it and use a previously worked out rate of descent and magically see the grass as he was about to flare.


I remember thinking about doing the same thing in Sudbury, using the pulp mill plume (very smelly, but clearly in view), but I was an F/O in those days, and convincing the Captain was too much work.

[chevvron]

100 feet Decision Height in the primitive cockpit of a Hurricane (by todays standards) is Cat 2 ILS minima today. That would require superb manual instrument flying skills. One rarely sees those sort of skills nowadays.

If not using an ILS with associated marker beacons, what instrument landing approach would have been used in those days to ensure tracking accuracy for the equivalent of a Cat 2 ILS?

Would that have been a GCA in 1943? if so, would the GCA in those days have marker beacons (aural only or cockpit lights) for height checks. Or would that be a BABS beam approach in 1943?

There wasn't much alternative in those days apart from a letdown using one of Mr Irvin's products.

[innuendo]

It consisted of an MF beacon that radiated along the approach path giving continuous 'A's when port of track and continuous 'N's when starboard. When on track they merged to a continuous note. There was an outer and inner marker which where passed at a certain height. IIRC these were 1,500 ft. and 100 ft..

Sounds very much like the precursor to the Radio Range system of navigation that we had to learn in the Link and back seat of the Harvard a long time ago.
It carried through to the early sixties where, once a year, we had to demonstrate a SJRA, (Standard jet range approach), from the back seat, under the hood, in a T-33 to renew our instrument ticket while on squadron.

Anyone remember how to do the Lost Orientation on the range. ?????

[megan]

Alex Henshaw apparently did it regularly using the plume of smoke from the factoryUsed in an operation flying home from oil rigs offshore, hot air from the gas plant next door to home would cause a localised bump in the top of the undercast, no approach aids, we were VFR after all. :p Military ground school instructor told of his days flying DC-3 in Sth. America, airport, an all over field, frequently the subject of fog but steeple of church always protruded, over the steeple at certain altitude and heading and let down at certain rate till the wheels made contact.

[Fareastdriver]

Same with Oakington with Vampires. On a damp day in the afternoon crud would rise to about 200 ft. The trick was to find Ely Cathedral which was on top of a hill in the town and was always above the fog. Over the top heading 230 which was an extension of runway 23 at Oakington for three minutes at 180 knots.

After two minutes drop down to 500 ft and at three minutes you could see the approach lights through the gloom. Drop the flaps and clogs and land.

[rogerg]

Did an NDB at a big grass field once, I was still in the clag at minima and was just about to go around when the tower advised to come down 10ft and all would be OK. Did that and it was as the tower could see my wheels poking out of the bottom of the clag. Those were the days!!

[BSD]

Centaurus,

I love your thought provoking posts. Always interesting and informative. One of the better reasons for reading PPRUNE. Like the back pages of "Flight" magazine used to be, should be a necessary read for all young pilots.

This one brings to mind that wonderful episode of "i learned about flying from that" published in Flying magazine about the C-124 Globemaster caught out in fog over Germany.

Cue: someone smarter than me who can find the link to it and repost it here. It has been posted and discussed on PPRUNE before.

Raises your pulse rate just reading it.

BSD.

[kenparry]

Lots of things were done to minima that, these days, would make one shudder. Bear in mind that the associated loss rate was high, too.

A couple of military instances: my first instructor had flown Air Defence Hunters in Germany in the mid-50s. Before the days of the Hunter T7, each Sqn kept a Vampire T11 which was used, among other things, as a weekend taxi. No such thing as minima - they would take a GCA which ended with "touchdown point now", at which stage power went to idle and they would hope to be on the hard bit.

Second, a former colleague who flew the CF-100 with the RCAF. They routinely flew with minima of "hundred and a quarter" - i.e. decision height of 100 ft and vis of 440 yds; I think this was also with GCA.

And remember what the Aeropostale did with the DC-3 and the like: using non-precision aids into grass fields and landing in fog. Minima? Not sure they had any.

It goes to show that you can get away with a lot - some of the time,

[BSD]

Ken,

Frederick Forsyth must have had that Vampire T11 in mind when he wrote “The Shepherd”

Aeropostale was an incredible operation, but in Sainte-Exupery’s book “Wind, Sand and Stars” where he writes extensively about Aeropostale in its infancy he wrote:

“One must remember, navigating by the compass and the stopwatch above cloud over the mountains (of Spain) is all very well, but below the sea of cloud lies eternity”

As you say, it is surprising what you can get away with - some of the time!

[megan]

Right here BSD.

https://disciplesofflight.com/zero-zero/